首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   10635篇
  免费   1248篇
  国内免费   878篇
工业技术   12761篇
  2024年   31篇
  2023年   149篇
  2022年   244篇
  2021年   294篇
  2020年   309篇
  2019年   248篇
  2018年   254篇
  2017年   313篇
  2016年   390篇
  2015年   414篇
  2014年   639篇
  2013年   629篇
  2012年   717篇
  2011年   824篇
  2010年   663篇
  2009年   784篇
  2008年   807篇
  2007年   880篇
  2006年   760篇
  2005年   657篇
  2004年   564篇
  2003年   504篇
  2002年   373篇
  2001年   224篇
  2000年   220篇
  1999年   156篇
  1998年   114篇
  1997年   98篇
  1996年   83篇
  1995年   71篇
  1994年   67篇
  1993年   28篇
  1992年   35篇
  1991年   34篇
  1990年   26篇
  1989年   28篇
  1988年   17篇
  1987年   9篇
  1986年   15篇
  1985年   18篇
  1984年   6篇
  1983年   11篇
  1982年   4篇
  1981年   4篇
  1980年   4篇
  1966年   4篇
  1965年   3篇
  1964年   5篇
  1962年   4篇
  1961年   4篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
考虑Hopfield模型中假态之间的布尔逻辑关系,提出利用IPA模型对神经网络中的假态进行抑制,并和原网络的性能进行了比较,结果表明:改进后的网络性能比Hopfield模型和IPA模型均有较大提高。  相似文献   
12.
该文在总结国内外高效离心风机的设计经验基础上,掌握和利用已有的经验,遵循一系列离心风机优化准则,成功的完成了高效机车用牵引电机通风机的设计.性能样机经台架试验,比原风机的性能有较大幅度的提高,效率达到86%,在国内同样风机中效率是较高的.  相似文献   
13.
Recent psychological research has investigated how people assess the probability of an indicative conditional. Most people give the conditional probability of q given p as the probability of if p then q. Asking about the probability of an indicative conditional, one is in effect asking about its acceptability. But on what basis are deontic conditionals judged to be acceptable or unacceptable? Using a decision theoretic analysis, we argue that a deontic conditional, of the form if p then must q or if p then may q, will be judged acceptable to the extent that the p & q possibility is preferred to the p & not-q possibility. Two experiments are reported in which this prediction was upheld. There was also evidence that the pragmatic suitability of permission rules is partly determined by evaluations of the not-p & q possibility. Implications of these results for theories of deontic reasoning are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
14.
Three photoconductive diamond detectors with highly oriented diamond (HOD) films fabricated by the same process were characterized with respect to temporal response, spectral responsivity and its spatial uniformity over the wavelength range from 190 to 250 nm. Temporal measurements showed a drift in the baseline, suggesting the presence of deep level carrier traps. The responsivity of specimen No. 2 was more than twice those of the other two specimens, but it showed an unpredictable current fluctuation. It was found that the spatial uniformities of all the specimens were too low for radiometric purposes. A prominent peak, thought to be due to photoemission, was found in the responsivity spatial distribution of specimen No. 3 under a negative applied voltage.  相似文献   
15.
形象思维足语文教学内容的一个重要组成部分,是语言表达的基础.语文课应该重视对学生形象思维的培养与训练.  相似文献   
16.
In this work, the instantaneous data of inner wall temperatures obtained at given axial positions but for different heated tubes or at various axial positions but at the same heated tube in a tube-bank fluidized bed evaporator with a vapor–liquid–solid external natural circulation flow were analyzed by employing linear and nonlinear time series analysis methods, including correlation dimension and Kolmogorov entropy analyses besides time domain, power spectrum and autocorrelation analyses. It is found that nonlinear characteristics of the wall temperature time series vary with spatial position in the evaporator at given operation conditions, and thus the multi-phase flow boiling behavior. However, the signals obtained at given axial position but different heated tubes in the evaporator exhibit more similar nonlinear evolution behavior, and those measured in the same heated tube but at different axial heights in the evaporator undergo more distinct nonlinear dynamic behavior. Multi-scale phenomena in different spatial positions are also found and discussed. These transient aspects of inner wall temperatures are closely related to the average holdup of solid particles and motion of vapor bubbles in vapor–liquid–solid flow. These results can provide some valuable information on the system modeling and controlling from the point of view of nonlinearity.  相似文献   
17.
Motion picture films are susceptible to local degradations such as dust spots. Other deteriorations are global such as intensity and spatial jitter. It is obvious that motion needs to be compensated for before the detection/correction of such local and dynamic defects. Therefore, we propose a hierarchical motion estimation method ideally suited for high resolution film sequences. This recursive block-based motion estimator relies on an adaptive search strategy and Radon projections to improve processing speed. The localization of dust particles then becomes straightforward. Thus, it is achieved by simple inter-frame differences between the current image and motion compensated successive and preceding frames. However, the detection of spatial and intensity jitter requires a specific process taking advantage of the high temporal correlation in the image sequence. In this paper, we present our motion compensation-based algorithms for removing dust spots, spatial and intensity jitter in degraded motion pictures. Experimental results are presented showing the usefulness of our motion estimator for film restoration at reasonable computational costs. Received: 9 July 2000 / Accepted: 13 January 2002 Correspondence to:S. Boukir  相似文献   
18.
C/C + +源代码风格检测工具的实现   总被引:1,自引:0,他引:1  
陈丹伟  李军  刘继兴 《计算机应用》2003,23(10):140-142
文中给出了评价C/C 源代码风格的规则分类和检查工具的总体结构,阐述了代码检查工具的核心技术——扩展词法分析和扩展语法分析,给出了代码检测工具的应用实例。  相似文献   
19.
一种固定阈值的毫米波图像边缘检测方法   总被引:1,自引:0,他引:1  
文章提出了一种固定阈值的毫米波图像边缘检测方法。根据图像的统计特征确定出像素的标准梯度强度,并采用单阈值对图像进行边缘粗定位,然后施行非最大抑制处理和滤波,得到最终检测结果。由于该算法对各幅毫米波图像设置相同的阈值,故能实现自动检测,同时还具有计算量小的特点。实验结果表明该方法进行毫米波图像边缘检测的有效性和可行性。  相似文献   
20.
This paper explains the manufacturing process of a composite train carbody with a sandwich composite structure for bodyshell and a stainless steel structure for the under frame. In addition, the structural behavior and safety of the composite carbody of the Korean tilting train was investigated by the static load tests. From the test results, the stiffness of the composite carbody met the specified design. In the aspect of strength, the maximum stress of the composite bodyshell was of 12.2% of strength of CF1263 carbon/epoxy.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号